GENERATION OF INSECTS. 21 



of the same colour, sometimes upon the branches of 

 the rose-tree, but more frequently, as we have ob- 

 served, upon some smooth object contiguous. For 

 several successive seasons, we have found more than 

 one group of these eggs upon the glass panes, as 

 well as the frame work, of a window, beneath which 

 a rose-tree has been trained. At present (January 

 1830) there are two of these groups on one pane, 

 and three on the frame-work; and as each contains 

 about fifty eggs, should they all be successfully hatch- 

 ed, two or three hundred caterpillars would at once be 

 let loose, and, streaming down simultaneously upon the 

 rose-tree beneath, would soon devour the greater 

 number of its buds. As the window faces the east, 

 the sudden appearance of the insects would make it 

 appear not unplausible that they had been swept hither 

 by an easterly wind. 



We found, durino; the same winter, an extraordina- 

 ry number of similar groups of the eggs of a leaf^ 

 roller {Lozotcenia Ribcana'^) on the branches of the 

 gooseberry and red-currant, in a garden at Lee. 

 On some small trees, from two to ten groups of eggs 

 were discovered; and as each group consisted of 

 from thirty to fifty, a caterpillar might have been 

 hatched for every bud. After the severity of the 

 season was over, we had the piece of bark cut off 

 on which these eggs were attached; and though they 

 had been exposed on the bare branches to the intense 

 frosts of 1829-30, they were hatched in a few days 

 after being brought into our study. As the currant- 

 trees were not then come into leaf, we had no food to 

 supply them with, and they refused the leaves of all 

 other plants which we offered to them. Had they 

 been permitted to remain on the trees till they were 

 hatched, they would probably have not left a single 

 leaf undevoured. For tliis spring, at least, these 

 currant bushes will be safe from their attacks, and of 



